Smaller electrically powered vehicles, typically called electric cars or electric carts, are widely used on golf courses and for a variety of electric utility vehicle applications. Although electric golf cars have become widely accepted, they typically require recharging after about to 36 holes of golf. Therefore, a typical 18 hole golf course requires about 80 cars to serve the golfers each day and a building large enough to house all the golf cars at night, during which they are commonly recharged. The recharging process not only takes time, but recharging during daytime hours can significantly increase the cost of electricity as a result of increasing peak demand charges from the utility to the customer.
The present invention relates to several aspects of an electric vehicle with a photovoltaic (PV) roof assembly which permits the batteries on an electric vehicle, typically referred to as an electric car or electric cart, to be charged during operation resulting in several benefits. These benefits include extending the range of the electric car because the batteries are charged during operation. The cost of using electricity from the utility to charge the cars is reduced because the batteries are typically at least partially charged by the solar charging during use. The battery life of the car can be extended because the depth of discharge can be reduced during normal use of the car. By increasing the length of time required between charges, labor costs incurred in the process of charging the batteries are reduced. Cars can be used more efficiently, thus possibly reducing the number of cars required by the facility. Finally, there are also benefits to the environment resulting from the reduced use of electricity from the electric utility and the potential need for fewer cars.
A first aspect of the invention is directed to an electric vehicle of the type including a vehicle body carrying a motor, a battery and a main PV assembly, the main PV assembly being coupled to the battery so to charge to battery. This improved electric vehicle includes a display unit mounted to the body, the display unit being electrically isolated from the battery and the main PV assembly. A secondary PV assembly is mounted to the body and is electrically connected to the display unit so the display unit provides an indication proportional to the intensity of the solar irradiation on the secondary PV assembly.
Another aspect of the invention is directed to an electric vehicle PV roof assembly including a vehicle roof comprising an upper surface having a number of assembly mounting element recesses. A PV assembly is secured to the upper surface of the roof of using PV assembly mounting elements at the mounting element recesses. The mounting elements are configured so that they do not shade the PV assembly.
A further aspect of the invention is directed to an electric vehicle PV roof assembly comprising a vehicle roof having an upper surface with first and second surface portions. A PV assembly is mounted to the first surface portion and a global positioning device, such as the ground plane of a global positioning system or a global positioning system antenna, is mounted to the second surface portion. The vehicle roof may include an opening through which the wires from the global positioning device can pass. Further, the second surface portion of the upper surface may include raised portions so to provide ventilation regions between the PV assembly and the upper surface. The upper surface may also include a depression positioned to accommodate wires exiting the PV assembly.
A still further aspect of the invention is directed to an electric vehicle PV roof including a PV roof body having a PV assembly-supporting upper surface, a peripheral edge circumscribing the upper surface, and a peripheral gutter formed between the upper surface and the peripheral edge. The gutter has a chosen minimum depth below the upper surface. The chosen minimum depth may be at least about 6 mm and the width of the gutter may be at least about 3 mm.
Another aspect of the invention is directed to an electric vehicle roof comprising a roof body with front and rear edges and lateral side edges. Hand-hold recesses are formed into the lateral sides at chosen positions. Hand-hold elements are mounted within the hand-hold recesses at positions to provide a minimum gap between the hand-hold elements and the lateral sides. The minimum gap is preferably at least about 2.5 cm.
Other features and advantages of the invention will appear from the following description in which the preferred embodiments have been set forth in detail in conjunction with the accompanying drawings.